Locking system for rolling-type tricycle

ABSTRACT

A locking system for a tricycle, including a braking mechanism, a rolling restraint mechanism, a driving mechanism which drives the braking mechanism and the rolling restraint mechanism, a control mechanism for applying control signals, and a detecting mechanism for applying a speed signal to the driving mechanism when a vehicle speed is lower than a predetermined value. The driving mechanism selectively or simultaneously drives the braking and restraint mechanisms in response to the control signal, and also drives the restraint mechanism upon receiving the speed signal. With such arrangement, maximum freedom is afforded the driver in assuming a desired posture, even when the tricycle is travelling under low inertia.

Background of the Invention

1. Field of the Invention

The present invention relates generally to a locking system for atricycle of the rolling type. More particularly, the invention relatesto a locking system for a tricycle having a wheel braking mechanism, arolling restraint mechanism and a control mechanism for the former twomechanisms.

2. Description of Relevant Art

In a motor driven tricycle having one front wheel, two rear wheels andfront and rear bodies coupled together through a supporting shaft forrelative rolling movement, it is well known to provide a locking systemcomprising a braking mechanism for braking the two rear wheels, arestraint mechanism for locking the front body against rolling thereofand a control mechanism for causing the braking mechanism and therestraint mechanism to brake and lock, respectively.

In such a conventional rolling-type tricycle, problems have arisen withrespect to improving convenience in handling of the tricycle as well asthe degree of comfort afforded the driver by functionally combining thewheel braking mechanism, the rolling restraint mechanism and the controlmechanism for the former two mechanisms. In a particular tricycle of thetype in which the driver's feet can be rested on a low level floor whendriving, it is important to permit the driver to assume a riding postureas freely as possible even when the tricycle is in a state of having arelatively low or substantially no moving speed.

The present invention effectively overcomes the aforesaid problemsattendant the conventional locking system of a rolling-type tricycle.

Summary of the Invention

The present invention provides a locking system in a rolling-typetricycle having front and rear bodies coupled together so as to permitrelative rolling movement therebetween. The locking system includes abraking mechanism for braking at least one wheel of the tricycle; arestraint mechanism for locking the relative rolling movement; a drivingmechanism for selectively or simultaneously causing the braking andrestraint mechanisms to perform braking and locking operations,respectively, in response to predetermined first signals, and forcausing the restraint mechanism to perform a locking operation inresponse to predetermined second signals; a control mechanism forapplying the first signal to the driving mechanism; and a detectingmechanism for detecting the speed of the tricycle and for applying thepredetermined second signal to the driving mechanism when the speeddetected is lower than a predetermined value.

An object of the present invention is to provide, in a rolling-typetricycle having a wheel braking mechanism, a restraint mechanism and acontrol mechanism for the former two mechanisms, in the form of alocking system which permits a driver to assume a riding posture asfreely as possible even when the tricycle has a low speed of travel.

The above and further objects, details and advantages of the presentinvention will become apparent from the following description ofpreferred embodiments thereof, when read in conjunction with theaccompanying drawings.

Brief Description of the Drawings

FIG. 1 is an elevational view schematically showing the right side of arolling-type tricycle provided with a locking system in accordance withthe present invention, which is partly broken away around a swingablejoint.

FIG. 2 is an enlarged view showing an essential portion of the swingablejoint illustrated in FIG. 1, which is partly broken away.

FIG. 3 is a view showing the right side of the swingable joint shown inFIG. 2, with the cover thereof being removed and the swingable jointpartly broken away, and with the operational position of the lockingsystem, when a braking cable is being pulled, being shown by a phantomline.

FIG. 4 is a view similar to FIG. 3, showing in phantom line theoperational position of the locking system during relatively high speedoperation of the tricycle.

FIG. 5 is a view similar to FIG. 3, showing in phantom line theoperational position of the locking system when a control cable is beingpulled.

FIG. 6 is an enlarged perspective view showing the essential portion ofthe locking system disposed in the swingable joint illustrated in FIG.2, the locking system being partly exploded.

FIG. 7 is an enlarged transverse-sectional view showing a speeddetecting mechanism in the locking system shown in FIG. 1.

FIG. 8 is a cross-sectional view taken along line 8--8 in FIG. 7.

FIG. 9 is a cross-sectional view taken along line 9--9 in FIG. 7.

Detailed Description of Preferred Embodiments

With reference to FIG. 1, there is shown a tricycle 1 having a main bodydivided into a front body 2 and rear body 3. The front body 2 isprovided in the front portion thereof with a front wheel 5 which issteered through a front fork 4 extended upwardly and provided with ahandlebar 6 at the top end thereof. A headlight unit 7 is attached tothe handlebar 6 at the intermediate portion of the latter. Further, aseat post 8 provided at the top end thereof with a seat 9 is disposed soas to extend upwardly in the rear portion of the front body 2. On a rearframe 10 defining the main portion of the rear body 3 is mounted anengine 11 having a gear casing 12 connected thereto. Two rear wheels 13,which are drive wheels, are respectively provided on the left and rightsides of the gear casing 12. The engine 11 and the casing 12 are coveredby a cover 14.

A swingable joint 15 is pivotally mounted through right and left bossportions 15a at its front end to the lower rear end of the front body 2by means of a pin 16 so as to be vertically swingable about the pin 16.A cushion unit 17 is pivotally connected as its lower end to the bossportion 15b projecting upwardly from the rear portion of the joint 15and is pivotally connected at its upper end to the intermediate portionof the seat post 8.

With reference to FIG. 2, the joint 15 is rotatably fitted through abearing 19 to the front portion of a supporting shaft 18 secured to therear frame 10 and extending in the longitudinal direction thereof, so asto be swingable around the supporting shaft 18, i.e., the front body 2is capable of rolling relative to the rear body 3. Preferably, aNeidhart damper (not shown) is installed in the joint 15 so as to bedisposed around the supporting shaft 18, thereby easing rotatingmovement around the supporting shaft 18. The joint 15 has a hollowcasing having its lengthwise axis extending substantially in thelongitudinal direction of the tricycle, and is provided with a pluralityof flexible control discs 21 (defining first disc members) carried by aholder 20 of a clutch inner type which is fitted onto the front portionof the supporting shaft 18 and a plurality of braking discs 22 (definingsecond disc members) each of which is disposed in each annular groove15d formed in the inner wall of the front portion 15c of the joint 15,and each being arranged between adjacent control discs 21. A pressureplate 24 (defining a pressing member) which is urged by a spring 23 tomove away from the free end of the supporting shaft 18, i.e., in therightward direction in FIG. 2, and which has at its center a boss 24aabutted against an eccentric cam 25, is arranged so as to oppose thefree end of the shaft 18 and is held by the inside wall of the frontportion 15c of the joint 15. The swinging motion, in the leftwarddirection, of a locking arm 26 (defining a third input portion and asecond output mechanism), which is shown by a chain line A in FIG. 2 inits leftward moved position and which is connected in its base portion(defining a second output portion) to a crank pin 25a fitted to theeccentric cam 25, forcibly moves the boss 24a of the pressure plate 24so as to frictionally engage both groups of the discs 22, 21 with eachother, to thereby lock the rotation of the joint 15 around thesupporting shaft 18, resulting in the front body 2 being locked againstrolling motion thereof.

Referring to FIGS. 3 through 6, the front wall 15f of a recess 15e whichis formed in one side of joint 15, for example in the right side in thisembodiment, is secured with the lower end of the outer flexible tube 27bof a brake cable 27. The upper end of the inner cable 27a of the brakecable 27 is connected to a control member, such as for example a brakelever or a brake pedal (not shown). The lower end of the inner cable 27ais connected through a rounded connecting pin 27c to the front end 28aof an equalizer holding plate 28 (defining a first input portion), whichis suspended in the front portion of the recess 15e and which has alongitudinally elongated shape and is formed with a first elongated hole28c extending longitudinally in the intermediate portion 28b thereof. Afirst output portion in the form of an equalizer 29 having left andright plate members 29a, 29a between which the intermediate portion 28bof the plate 28 is disposed, is connected at the upper rear and lowerrear ends thereof through rounded connecting pins 30c with the forwardends of the inner cables 30a of two brake cables 30 for operatingbraking devices (not shown), so as to brake the left and right rearwheels 13. A first pin 29b, fitted to and crossing through theintermediate portion of the equalizer 29, is slidably engaged in theelongated hole 28c.

Accordingly, when the inner cable 27a of the brake cable (defining afirst input member of a first input mechanism) is pulled so as to supplya first signal, the plate 28 is moved forwardly (rightwardly in FIGS. 3through 5) as shown by a chain line B in FIG. 3, the equalizer 29engaged through the elongated hole 28c is also moved as shown by a chainline C, and therefore the inner cables 30a (together defining a firstoutput mechanism) are pulled so as to brake both rear wheels 13. InFIGS. 3 through 5, reference numeral 31 denotes supporting portions eachserving as both a guide for each of the upper and lower cables 30 and astopper for the equalizer 28. Further, the forward ends of the outerflexible tubes 30b of the brake cables 30 are secured to the rear wall15g of the joint 15.

The rear end of the rear portion 28d projecting rearwardly from theplate 28 defines a fifth input portion which is pivotably connectedthrough a pin 32b to the intermediate portion of a first link 32, theupper end of which is swingably and pivotably supported with a pin 32aas a pivot by the inside wall of the recess 15e and the lower end ofwhich is pivotally connected through a pin 32c to the lower end portionof a second link 33. Each link 32, 33 comprises a unitary member definedby left and right elongated plates, the first link 32 being positionedbetween the plates of the second link 33 which allow the inner cable 30ato pass therethrough for extending rearwardly. Further, a coupling pin33a provided at the upper end or free end of the second link 33 ishooked by one end of a spring 34 (defining a third output portion), theother end of which is connected through an adjusting member 35, forsuitably adjusting a spring load by the spring 34, to a bent andsuspended portion 26a or forward end portion of the locking arm 26.

Between left and right arm portions 36a of an actuating plate 36(defining a sixth input portion) having a substantially U-shape isloosely held the intermediate portion of the second link 33. A third pin33b provided in the intermediate portion of the second link 33 isloosely fitted in third elongated holes 36b each formed in each of theleft and right arms 36a and extending in the longitudinal direction. Therear end of the actuating plate 36 is coupled to the forward end of theinner cable 37a of an actuating cable 37 (defining a second inputmechanism). The forward end of the outer flexible tube 37b is secured toa wall 15g through an adjusting member 38.

Upon braking by means of the pulling action of the cable 27 which causesthe plate 28 to move rightwardly in FIG. 3, the first link 32 swingscounterclockwise around the pivot pin 32a, and therefore the second link33 is also moved rightwardly through the pin 32c, so as to assume theposition shown by a chain line D in FIG. 3. However, because the pin 33bof the second link 33 slides along the elongated hole 36b, no force inthe rightward direction in FIG. 3 is exerted on the actuating plate 36.Accordingly, the input force of braking is isolated from the cable 37a.

Referring to FIGS. 7 through 9, in the gear casing 12 there is provideda driven shaft 39 (defining a first shaft member) which is driven by agear 38a through a gear 39a meshed with the latter upon the rotation ofa wheel axle (not shown). The free end portion of the driven shaft 39 issecured with a holder 40b (defining a clutch outer member) holding aplurality of governor weights 40 (defining clutch inner members) adaptedto spread under the action of centrifugal force and inside which acylindrical detecting shaft 41 (defining a second shaft member) isrotatably fitted onto the shaft 39. A coarse thread portion 41a formedin the outer periphery of the detecting shaft 41 is threadedly engagedwith a slider 42 (defining a slidable member) having a coarse threadportion in the inner diameter portion thereof and urged by a spring 42ain the restoring direction thereof. A pin 43a, pivotally supporting afork member 43 (defining a lever member) which cooperates with theslider 42, is fitted in the base end portion of the arm 44 having theforward end thereof extending outwardly from the casing 12. The rear endof the inner cable 37a of the cable 37 is connected through a roundedconnecting pin 37c to the forward end of the arm 44.

When the wheel axle is rotated at a speed higher than a predeterminedvalue, rotation of the driven shaft 39 urges the governor weights 40 tospread so as to overcome the force of spring 40c (FIG. 8), the weights40 therefore separating from the detecting shaft 41, and thereby thedriven shaft 39 runs idly with the detecting shaft 41 not being moved.When the vehicle speed is lower than the predetermined value, theweights 40 are closed so as to engage with the detecting shaft 41 whichis therefore driven, causing the slider 42 which is engaged through thecoarse thread portions with the detecting shaft 41 to move leftwardly inFIG. 7 so that the fork 43 swings counterclockwise, overcoming the forceof spring 43b (FIG. 9), and the arm 44 also swings from a position shownby a chain line E to a position shown by a solid line in FIG. 7, tothereby pull the inner cable 37a.

Accordingly, when the inner cable 37a is pulled at the decreased speedwhich is lower than the predetermined value, including, of course, zeroor nil speed, thus supplying a second signal, the actuating plate 36connected with the forward end of the inner cable 37a is retarded, asshown in FIG. 4, so as to assume a position as shown by a chain line F,to thereby pull the pin 33b rearwardly by striking of the latter againstthe forward end of the elongated hole 36b in which the pin 33b isengaged. The second link 33 swings leftwardly in FIG. 4, i.e., in thecounterclockwise direction, around the pin 32c, the upper end of thesecond link 33 moving to a relatively large extent in the rearwarddirection, so that the links 32, 33 are opened, formed a substantiallyV-like shape as shown by a chain line G. As a result, the spring 34 isextended and the locking arm 26 swings counterclockwise, assuming aposition as shown by the phantom line A in FIG. 2, so that rotation ofthe joint 15 around the supporting shaft 18 is inhibited to lock therelative rolling between the front and rear bodies 2, 3.

In addition to the above-described construction, an actuating arm 45(defining part of a second input portion) for the parking brake, whichis provided at both ends of the boss portion 45b at the lower endportion thereof with spaced arm portions 45c, 45e and which is pivotallysupported by a pin 45a extending through the lower end portion, isdisposed in the lower intermediate portion of the recess 15e of thejoint 15. A substantially L-shaped engaging shoulder portion 45d isformed in the forward end portion of the arm portion 45c, and theaforesaid equalizer 29 is disposed between both arm portions 45c, 45ewith one projecting end 29c of the pin 29b being abutted against therear end of the engaging shoulder portion 45d. The other arm 45e isupwardly extended and has an upper forked end 45f to which the lower endof a rigid substantially L-shaped member 47 (defining a part of thesecond input portion), connected with the lower end of an outer flexibletube 46f of a control cable 46, is coupled through a rounded connectingpin 47a. The lower end of an inner cable 46a (defining a second inputmember and a fourth input portion) is connected through a second roundedconnecting pin 46c with a second elongated hole 26b formed in theforward end portion of the locking arm 26 as shown in FIG. 2. The upperend of the inner cable 46a of the cable 46 is connected to the baseportion of a parking brake control lever 49 (defining a lever member)which is pivotally fitted at the base portion thereof to the supportingmember 48 disposed between the seat post 8 and the seat 9. In FIG. 1,reference numeral 50 denotes a cover for covering the recess 15.

With the above-described arrangement, when a parking locking operationis performed by swinging the control lever 49 in the normal direction tothe plane of FIG. 1, the inner cable 46a is pulled so that the lower endof the inner cable 46a, on the one hand, having pin 46c engaged in theelongated hole 26b of the locking arm 26, is then secured at the extremeposition thereof; and the member 47, on the other hand, is pushed towardthe upper right in FIG. 5 under the reaction of such engagement. Becausethe rigid member 47 is substantially L-shaped, member 47 advances ormoves rightwardly in FIG. 5, assuming a position as shown by a chainline H, and the arm 45 swings clockwise around the pin 45a as a pivot,assuming a position as shown by a chain line I. As a result, the pin 29bis moved rightwardly by the engaging shoulder portion, assuming aposition as shown by a chain line J, so as to move the equalizer 29rightwardly as shown by a chain line K, causing the inner cable 30a tobe pulled to brake the rear wheels 13. In such operation, the pin 29bdoes not interfere with the normal brake control system for the rearwheels, because it slides in the elongated hole 28c of the plate 28.

As will be clearly understood from the foregoing detailed description,the manipulation of the parking brake control lever 49 actuates the rearwheel braking system, without interfering with the normal brake controlsystem, for locking the rear wheels simultaneously with the self-lockingaction to prevent rolling.

Although there have been described what are at present considered to bethe preferred embodiments of the invention, it will be understood thatthe invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiments are therefore to be considered in all respects asillustrative, and not restrictive. The scope of the invention isindicated by the appended claims rather than by the foregoingdescription.

I claim:
 1. A locking system in a rolling-type tricycle having front andrear bodies coupled together for relative rolling movement,comprising:means for braking at least one rear wheel of said tricycle;restraint means for locking the relative rolling movement of saidbodies; driving means, operatively cooperating with said braking meansand said restraint means, for causing said braking means and saidrestraint means to perform braking and locking operations, respectively,in response to predetermined first signals, and for performing saidlocking of said restraint means in response to predetermined secondsignals; control means for applying said first signals to said drivingmeans; and means for detecting a speed of said tricycle so as to applysaid second signals to said driving means when said speed is lower thana predetermined value.
 2. A locking system according to claim 1,wherein:said control means comprises a brake control mechanism forbraking said tricycle during travel thereof and a locking controlmechanism for braking said tricycle when parking, said first signalsincluding braking and locking signals applied through said braking andlocking mechanisms.
 3. A locking system according to claim 2,wherein:said driving means causes said braking means to perform saidbraking operation when said second signals are absent upon receipt ofsaid braking signal, and simultaneously causes said braking andrestraint means to perform said braking and locking operations,respectively, when said second signals are present.
 4. A locking systemaccording to claim 3, wherein:said driving means simultaneously causessaid braking and restraint means to perform said braking and lockingoperations, respectively, when said locking signal is received.
 5. Alocking system according to claim 4, wherein:said driving meanscomprises:first and second input mechanisms introducing said first andsecond signals, respectively; first and second output mechanisms coupledto said braking means and said restraint means, respectively; and alogical linkage network interposed between said first and second inputmechanisms and said first and second output mechanisms, and adapted tofunction logically; said logical linkage network including a firstlinkage interposed between said first input mechanism and said firstoutput mechanism, a second linkage interposed between said first inputmechanism and said second output mechanism, and a third linkageinterposed between said second input mechanism and said second linkage,said first input mechanism having first and second input members forintroducing said braking signal and said locking signal, respectively,and said first and second input members both being connected to saidfirst and second linkages.
 6. A locking system according to claim 5,wherein:said first, second and third linkages have first, second andthird switching mechanisms, respectively; said first switching mechanismcomprises first and second input portions (28, and 45, 47) connected tosaid first and second input members (27a, 46a), respectively, and afirst output portion (29) connected to said first output mechanism (30a,30a); said second switching mechanism comprises a third input portion(26) connected through said third switching mechanism to said firstinput portion (28), a fourth input portion (46a) connected to saidsecond input portion (45, 47) and a second output portion (26) connectedto said second output mechanism (26); and said third switching mechanismcomprises fifth and sixth input portions (28d, 36) connected to saidfirst input portion (28) and said second input mechanism (37a),respectively, and a third output portion (34) connected to said thirdinput portion (26).
 7. A locking system according to claim 6,wherein:said first and second switching mechanisms comprise first andsecond AND gates, respectively; and said third switching mechanismcomprises an inhibit gate which does not close unless a predeterminedsignal is received in said sixth input portion.
 8. A locking systemaccording to claim 7, wherein:said first and second AND gatesrespectively include first and second elongated holes and first andsecond pin members slidably fitted in said first and second elongatedholes, respectively.
 9. A locking system according to claim 8,wherein:said first input portion comprises a first linearly movablemember; said second input portion comprises a first pivotable memberinterferable with said first pin member; said first output portioncomprises a second linearly movable member secured with said first pinmember; said third input portion comprises the forward end of a secondpivotable member having formed therein said second elongated hole andhaving a base end which is pivotably supported; said fourth inputportion comprises a pullable member connected to said second pin member;and said second output portion comprises said base end of said secondpivotable member.
 10. A locking system according to claim 9,wherein:said second input portion further comprises a substantiallyL-shaped movable rigid pipe member having one end pivotally attached tosaid first pivotable member and a pullable cable extending through saidpipe member.
 11. A locking system according to claim 7, wherein:saidinhibit gate comprises a first link member having one end pivotallysupported, a second link member having one end pivotally supported bythe other end of said first link member, a third pin member secured tosaid second link member and a third elongated hole into which said thirdpin member is slidably fitted.
 12. A locking system according to claim11, wherein:said fifth input portion comprises a linearly movable memberpivotably attached to said first link member, said sixth input portioncomprises a movable member formed therein with said third elongatedhole, and said third output portion comprises a pullable member engagedwith the other end of said second link member.
 13. A locking systemaccording to claim 12, wherein:said pullable member is connected to saidthird input portion through a spring mechanism having an adjustablespring force.
 14. A locking system according to claim 5, wherein:each ofsaid first and second input members and said first output mechanismcomprises at least one pullable cable.
 15. A locking system according toclaim 5, wherein:said second output mechanism comprises a pivotablemember.
 16. A locking system according to claim 2, wherein:said brakingcontrol mechanism comprises a lever member disposed substantiallyproximal to a handlebar mounted on said tricycle; and said lockingcontrol mechanism comprises a lever member disposed below a driver'sseat mounted on said tricycle.
 17. A locking system according to claim1, wherein:said front and rear bodies are directly coupled togetherthrough a supporting shaft having a rear end secured to said rear bodyand a joint member having a rear portion rotatably fitted onto the frontend of said supporting shaft and a front portion swingably engaged withsaid front body.
 18. A locking system according to claim 17,wherein:said restraint means comprises a frictional mechanism interposedbetween said supporting shaft and said joint member.
 19. A lockingsystem according to claim 18, wherein:said frictional mechanismcomprises:a plurality of first disc members unitarily rotatable togetherwith said supporting shaft; a plurality of second disc members unitarilyrotatable together with said joint member; and a pressing member movablein a direction which causes said first and second disc members to beclosely contacted with each other.
 20. A locking system according toclaim 1, wherein:said tricycle includes two wheels carried by said rearbody.
 21. A locking system according to claim 20, wherein:said brakingmeans comprises braking mechanisms each operatively cooperating with oneof said rear wheels.
 22. A locking system according to claim 1,wherein:said detecting means comprises:a first shaft member rotatable inproportion to vehicle speed; a clutch mechanism operatively cooperatingwith said first shaft member; a rotatable second shaft member coupled tosaid clutch mechanism; a slidable member threadedly engaged with saidsecond shaft member and an output mechanism operatively cooperating withsaid slidable member.
 23. A locking system according to claim 22,wherein:said clutch mechanism comprises:a clutch outer member unitarilyrotatable with said first shaft member; and a plurality of clutch innermembers swingably and pivotably mounted so as to respond to centrifugalforce, said clutch inner members being pushingly contacted with theouter periphery of said second shaft member when said vehicle speed islower than a predetermined value.
 24. A locking system according toclaim 22, wherein:said output mechanism comprises a lever memberpushingly contacted by said slidable member toward the fixing positionthereof, and a cable member operatively cooperating with said levermember.